The main purpose of prophylactic rabies pre-exposure immunization (PrEP) is to induce an effective and rapid anamnestic antibody response after revaccination that obviates the need for human rabies immunoglobulins (RIG) and simplifies post-exposure immunization (PEP) to just 2 doses of rabies vaccine (D0, D3).
Many travellers decline pre-travel 3-dose PrEP because of costs and insufficient time between visit at the travel clinic and departure.
The aim of this study is to demonstrate that a single dose of rabies vaccine can induce an equally rapid and adequate anamnestic antibody response as 3-dose PrEP to revaccination six months later.
Travellers will be randomized between standard 3-dose PrEP, single dose PrEP (standard intramuscular dose or one-fifth fractional intradermal dose) and no PrEP before travel. After 6 months, all subjects receive a simulated 2-dose post-exposure vaccination schedule (D0 and D3).
Serum samples are collected at 0, 1, and 6 months after PrEP, and at 3, 7 and 28 days after the simulated post-exposure vaccinations.
The primary endpoint is the rate of increase of geometric mean concentrations (GMC) of neutralizing antibodies between day 0 and day 7 after revaccination for the different study groups.
If PrEP with a single dose of rabies vaccine would be equally effective in inducing a rapid and adequate anamnestic antibody response, RIG would not be no longer required in case of high risk bite wounds in (returning) travellers. Guidelines on pre-travel PrEP could be simplified. Pre-travel rabies PrEP would come within reach of most travellers.